The purpose of this basic qualitative research study was to identify the extent to which kindergarten teachers understand and implement inquiry-based instruction in their science classrooms. This study was conducted in response to the indication that traditional didactic teaching methods were not enough to adequately prepare American students to compete in the global economy. Inquiry is a teaching method that could prepare students for the critical thinking skills needed to enter society in the 21st century. It is vital that teachers be sufficiently trained in teaching using the necessary components of inquiry-based instruction. This study could be used to inform leaders in educational administration of the gaps in teachers' understanding as it pertains to inquiry, thus allowing for the delivery of professional development that will address teachers' needs. Existing literature on inquiry-based instruction provides minimal information on kindergarten teachers' understanding and usage of inquiry to teach science content, and this information would be necessary to inform administrators in their response to supporting teachers in the implementation of inquiry. The primary research question for this study was "To what extent do kindergarten teachers understand the elements of implementing inquiry-based lessons in science instruction?" The 10 participants in this study were all kindergarten teachers in a midsized school district in the Mid-Atlantic region of the United States. Data were collected using face-to-face semistructured interviews, observations of the teachers implementing what they perceived to be inquiry-based instruction, and the analysis of lesson plans to indicate the components used to plan for inquiry-instruction. The findings of this study indicated that while teachers believed inquiry to be a beneficial method for teaching science, they did not understand the components of inquiry and tended to implement lesson plans created at the district level. By analyzing the findings of this study, it became evident that kindergarten teachers could benefit from scaffolded, ongoing professional development focusing on the components of inquiry and how to implement inquiry in their science instruction. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]